Digital controllers that can be fully implemented in CMOS IC processes and have programmable parameters, such as switching frequency, voltage reference, and the accuracy of its regulation, can bring numerous advantages in low-power SMPS. In cell-phones, personal data assistants (PDA), and other portable devices, they can significantly reduce the overall system size, increase reliability, as well as battery operating time. To provide regulated voltages for various functional blocks, which in most of the cases are based on digital components, multiple application specific analog controller ICs are predominant. As a result, the systems often have a sub-optimal size and number of components. If implemented in the same CMOS process as their predominantly digital loads, the programmable controllers can be easily integrated on the same silicon die and programmed to satisfy specific power supply requirements. In addition to the resulting size reduction, they can provide design portability and can practically eliminate the time-consuming analog redesign, required each time the IC implementation technology and, hence, supply voltage requirements change.
Programmable controllers can simplify implementation of power savings techniques based on dynamic voltage scaling (DVS) where the supply voltage is changed in accordance with the processing load. They can eliminate the need for interconnecting circuits and improve communication between the power supply and its digital load.